1. Field of Invention
The present invention relates to a water saving technology of a water feeding apparatus, and more particularly to an air intake module of a water feeding apparatus capable of saving water, increasing pressure, and preventing back pressure leakage and clogging.
2. Related Art
Conventional shower heads are usually provided for users to take a shower, and some of shower heads are provided with a water flow switching mechanism, thereby changing the intensity of the water flow and the size of water splashes from the shower heads, and even producing a massaging effect in use by producing a rushing water flow through the design of intermittent water supply.
However, with global warming and climate changes, water resources become more and more precious, and many countries enacts regulations for water use mostly in the environmental protection spirit of reducing water consumption to save water. Thus, manufacturers of water feeding apparatuses are all devoted to creating low-flow and high-pressure water feeding apparatuses, so as to design a water feeding apparatus that reduces water consumption to save cost without affecting users' feeling of taking a shower.
A structure is disclosed in U.S. Pat. No. 7,416,171, entitled “VACUUM VENTURI APPARATUS AND METHOD”, in which first and second openings are disposed in a plug and the second opening is connected to the first opening, a diameter of the second opening is larger than that of the first opening, a third opening is disposed radially outward from the first opening, the first opening is connected to a water inlet end, the diameter of the first opening is smaller than that of the water inlet end, and the second opening is connected to a water outlet end. With the differences between the diameters of the water inlet end, the first opening, and the second opening, a Venturi Effect occurs when a water flow passes through the first opening, so as to draw air from the third opening, and the water flow is mixed with the air, thereby raising the water output pressure and reducing water consumption, so as to achieve the efficacy of water saving.
The use of the above vacuum venturi apparatus alone may not cause any problem. However, a current water feeding apparatus (for example, a shower head) is usually provided with a water flow switching mechanism in a front part, and when a user switches the water flow switching mechanism in use, a back pressure of a water flow is produced inside the shower head, which increases the pressure of the water flow inside the shower head, and thus causes the problem that the water flow is ejected from the third opening of the vacuum venturi apparatus.
Furthermore, when impurities such as water scale exist in the shower head, the back water flow may push the impurities such as the water scale to the third opening, which clogs the third opening, so the vacuum venturi apparatus loses efficacy.